My Annual Ryegrass Is Turning Brown

This wintertime species requires the same care as summertime grasses.

In mild climates that don't see snow-covered ground during the winter, most homeowners prefer to have a lawn that remains green year-round. Annual ryegrass (Lolium multiflorum) is often the solution since it's a cool-season grass that grows well during mild winters. Several causes can result in your annual ryegrass turning brown, including its short life cycle.

Life Cycle

Annual ryegrass, as its name implies, is an annual winter crop. Because of its annual growing tendency, annual ryegrass turns brown and dies at the end of its life, typically late spring or early summer. Unfortunately, this species often turns brown and dies before the warm-season grass has completely emerged out of dormancy, leaving the homeowner with a briefly brown or discolored lawn.

Drought Tolerance

Although annual ryegrass is considered a hardy cool-season grass and ideal winter cover, it doesn't come without problems. The species isn't particularly drought tolerant; this species prefers well-drained, moist soil and can tolerate temporary flooding. Regular watering is required when rain is absent; a period of drought can cause the annual ryegrass to prematurely brown. Begin watering less frequently and more deeply in spring to help the warm-season grass grow as it's coming out of dormancy.

Temperature Tolerances

Although this cool-season grass is ideal for greening up your lawn in winter, it's not tolerant of extreme highs or lows. Premature browning may occur if you experience an unusually cold winter. The grass may die long before the warm-season grass comes out of dormancy.

Crown Rust

Certain annual ryegrass cultivars are hosts of crown rust, a fungal disease that causes brownish-rust-colored spots on the leaves. Infected grass can look like it's starting to turn brown due to the oblong, rusty spots on the blades. These types of rusts are late-season diseases and are worse following cooler than normal springs. The best defense against this disease is using resistant cultivars of ryegrass.

Fertilizer Errors

Annual ryegrass requires the same type of care and maintenance that warm-season grasses do. Fertilizing helps the annual ryegrass look its best during the growing season. Apply only 1 to 2 pounds of nitrogen fertilizer per every 1,000 square feet of lawn from October to May. Too much nitrogen can burn the grass and leave brown spots; use a broadcast spreader and slow-release nitrogen fertilizer to help prevent this type of problem.